火灾中短路发生时周围的环境气氛对短路时导线上形成的熔化痕迹特征具有决定性影响。 为了探讨环境气氛中氧浓度对短路熔痕特征的影响, 文章对木材、 纸板、 泡沫、 橡胶、 塑料等典型燃烧物燃烧时燃烧部位的氧气浓度进行了测定, 确定了典型燃烧物燃烧时燃烧部位氧气浓度的极限条件。 选择100% N2, 10% O2+90% N2和20% O2+80% N2三种浓度的试验气体, 分别在3种气体环境下进行短路实验, 然后对得到的短路熔痕样品进行AES深度剖析, 得出短路熔痕样品表层平均氧含量与环境氧浓度成近似线性的对应关系。 因此可以根据测得的氧浓度, 确定出短路发生时的周围环境气氛条件, 推断其与火灾发生的关系, 进一步推断火灾原因。

The ambience has a critical effect on the characteristic of bead formed by fuse breaking of the electric copper wire in fire. In order to study the influence of oxygen concentration in surroundings on the characteristic of bead formed by fuse breaking, firstly, the oxygen concentration of typical things such as wood, paper, foam, rubber and plastic etc when they were burning was measured. The extreme conditions of oxygen concentration of typical things were ascertained when they were burning. Accordingly the oxygen concentration of simulated environment (100% N2, 10% O2+90% N2, and 20% O2+80% N2) was determined. Secondly, the in-depth composition of beads formed by fuse breaking of the electric copper wire in different circumstances was studied by AES. The relationship is almost linearity between the average oxygen concentration and the ambient oxygen concentration. Consequently, from the measured oxygen concentration, the authors can deduce the ambient oxygen concentration and the fire cause.